setTimeout(
    function(){
        console.log(1)
    },0); 
new Promise(
    function(resolve,reject){
        console.log(2);
        resolve();
    })
    .then(function(){
        console.log(3)
    })
    .then(function(){
        console.log(4)
    });
process.nextTick(function(){
    console.log(5)
}); 
console.log(6);

//2 6 5 3 4 1